All this talk about metabolism made me curious so I did a little research about it so I could give you the facts of my findings. Metabolism is the process by which the nutrients in the food we eat are broken down in our cells to produce energy for our body. Most of the time when people talk about metabolism they are actually talking about BMR (Basal Metabolic Rate) which is the number of calories your body burns over a set period of time. Your metabolism is controlled by the thyroid gland in the neck which is controlled by the hypothalamus. The speed of your metabolism depends on the complex chemical messages sent from your body to your brain telling it how much it needs to keep going. Body size and composition determine how much food you need to produce energy so the heavier you are the more energy your body need to consume to keep going, so you actually have a higher metabolic rate. Think of it like a big luxury car vs. a compact car, it takes more fuel to run the big car than it does the small car, same applies to people.
As unfair as this is, men have a higher metabolism than women. Men have more muscle and since it is more “metabolically active” than fat, it burns more energy, even at rest. Although a large man may actually have a slower metabolism than a slim woman with more muscle tissue. Age is also a factor, as it slows down slightly with age due to loss of muscle tissue as we get older. Making it that more important to stay physically active the older we get. Exercise and increased activity levels can increase your metabolism because you breathe harder and your heart rate increases, which in turn causes a demand for more energy. Although, it needs to be vigorous to make a significant difference and your metabolic rate goes back to normal as your hear rate recovers. Regular exercise, especially strength training (free weights, weight machines) all build muscle and the greater your muscle mass the higher your BMR.
The thyroid is always the villain. Having an underactive thyroid must be the problem if you are gaining weight right? Not always, it would require an extremely under active thyroid (clues would be extreme fatigue, depression, dry skin and hair, and a loss of sex drive) to be the cause. Taking a look at what you are eating and portion size could be the issue, but if you have any of the symptoms listed, check with a doctor immediately. People swear by ephedrine which can speed up metabolism and decrease appetite, but it increases heart rate and blood pressure which could be dangerous so it is best to stay away from it. Caffeine and red chilies can raise BMR briefly, but the effects are too small to bother with and the side effects are the same as ephedrine so you are better off saving your money, eating a little less and going for a brisk walk.
So you want to know how many calories to consume every day? Here’s what you need to know when figuring how many calories you should be ingesting daily http://www.caloriesperhour.com/tutorial_need.php:
1. You Resting Metabolic Rate (RMR) http://www.caloriesperhour.com/tutorial_BMR.php accounts for 70% of the calories you burn just to stay alive (in order to keep breathing, making sure your heart beats and blood pumps around your body)
2. Around 12% of your calories are used for thermogenesis – what you need to keep warm, digest food and respond to stress.
3. The rest are burned doing daily tasks or more strenuous exercise.
